package lab02.test02;

public class Circle {
    //1、属性
    double r;
    double π;
    double girth;
    double area;

    //2、行为(方法、函数)
    public double Girth(){
        girth = 2*r*π;
        return girth;
    }
    public double Area(){
        area = π*r*r;
        return area;
    }
    //3、构造函数
}
